Pass format as argument to getContentBitmapAsync.

content/public/android/javatests/src/org/chromium/content/browser/ContentViewReadbackTest.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.content.browser;
 
 import static org.chromium.base.test.util.ScalableTimeout.scaleTimeout;
 
 import android.graphics.Bitmap;
 import android.graphics.Color;
@@ skipping 97 matching lines @@
                     public void onFinishGetBitmap(Bitmap bitmap) {
                         assertNotNull("Readback did not return valid bitmap", bitmap);
                         // Verify a pixel in the center of the screenshot.
                         color.set(bitmap.getPixel(bitmap.getWidth() / 2, bitmap.getHeight() / 2));
                         readbackDone.set(true);
                     }
                 };
 
                 contentReadbackHandler.initNativeContentReadbackHandler();
                 contentReadbackHandler.getContentBitmapAsync(1.0f, new Rect(), getContentViewCore(),
-                        callback);
+                        Bitmap.Config.ARGB_8888, callback);
             }
         });
         assertWaitForReadback(readbackDone);
 
         assertEqualColor(color.get(), Color.BLUE, COLOR_THRESHOLD);
     }
 }